Alzheimer's disease is the most common form of dementia in Australia and may contribute to 60-70% of cases.

Most people who develop Alzheimer's Disease are over 65 years of age, however it is estimated that in Australia in 2011 there are 23,900* individuals living with Younger Onset Dementia i.e. under 65 years of age.

Alzheimer's disease is a progressive, degenerative condition that attacks the brain, causing changes to memory, thinking and behaviour. Symptoms usually develop over time, early symptoms can be very subtle. As the disease progresses, symptoms become more noticeable and interfere with daily life. As brain cells shrink or disappear abnormal material builds up such as tangles in the centre of the brain cells and plaques outside the brain cells.

These abnormalities disrupt messages within the brain, damaging connections between brain cells. The brain cells eventually die and this means that information cannot be recalled or assimilated.

As Alzheimer's disease affects each area of the brain, certain functions or abilities are lost. While Alzheimer's disease will affect each person differently and symptoms experienced can vary, common symptoms may include (Ref: Alzheimer's Australia):

Persistent and frequent memory loss, especially of recent events

Vagueness in everyday conversation

Being less able to plan, problem solve, organise and think logically

Language difficulties such as finding the right word and understanding conversations

Apparent loss of enthusiasm for previously enjoyed activities

Taking longer to do routine tasks

Becoming disoriented, even in well-known places

Inability to process questions and instructions

Deterioration of social skills

Emotional unpredictability

Changes in behaviour, personality and mood

For more information on types of dementia see Alzheimer's Australia's helpsheets, About dementia

Unravelling the Genetics of Alzheimer's

Being that Alzheimer's disease is the most common type of dementia it is in less than 1% of cases that Alzheimer's can be passed down in families.

Alzheimer's Research UKhas produced a video that reveals the genetics and risk factors associated with the disease.